HP ServiceGuard Arun prasath S

February, 2014

• No single point of failure• Negligible downtime

What is ‘High availability’ ?

What is ‘ServiceGuard’ ?

• HP’s software to create HA Clusters• Available for Linux and HP-UX

ServiceGuard Architecture

ServiceGuard - Daemons

• /usr/lbin/cmclconfd - Serviceguard Configuration Daemon• /usr/lbin/cmcld - Serviceguard Cluster Daemon• /usr/lbin/qs - Serviceguard Quorum Server Daemon• /usr/lbin/cmnetd - Serviceguard Network Manager daemon• /usr/lbin/cmlogd - Serviceguard Syslog Log Daemon

Typical cluster

Cluster after failover

Package ? How it runs ?

Services + disk volumes + Floating IP Addresses + Other resources

Eg: httpd + ‘/disk/page/ ’ + 192.168.145.100

=Package

Package time line

Clusters

192.168.145.12

192.168.145.10 192.168.145.11

192.168.145.13

192.168.145.100

Client

Clusters have problems

“Split brain syndrome”

I am a cluster and I am going to access the

disk

I am a cluster and I am going to access the

disk

192.168.145.10 192.168.145.12192.168.145.11 192.168.145.13

Solution #1 for Split brain syndrome

“Lock disk”

Solution #2 for Split brain syndrome

“Quorum server”

Demo architecture

192.168.145.11sglq

(Quorum server)192.168.145.9

sglx192.168.145.10

sglxa

sglx_cluster192.168.145.100

Client

‘Package’ on shared disk ( ‘DocumentRoot‘ location )

Demo implementation flow

1. Setup hardware1. Install Redhat on 3 servers (sglx, sglxa, sqlxq)2. Setup redundant network and power connections 3. Setup a shared storage

2. Install ServiceGuard1. Install ServiceGuard packages in 2 servers (sglx and sglxa)2. Install quorum server packages in 1 server (sglxq)

3. Install Apache web server1. Install apache in the 2 servers (sglx and sglxa)2. Configured ‘DocumentRoot’ to shared storage location

4. Create and configure cluster configuration file 5. Create and configure package configuration file6. Apply configuration to broadcast changes7. Run cluster and packages

Links

• Download link : https://h20392.www2.hp.com/portal/swdepot/displayProductInfo.do?productNumber=SGLX-DEMO

• Manuals: http://h20566.www2.hp.com/portal/site/hpsc/template.PAGE/public/psi/manualsResults/?sp4ts.oid=4162060&spf_p.tpst=psiContentResults&spf_p.prp_psiContentResults=wsrp-navigationalState%3Daction%253Dmanualslist%257Ccontentid%253DUser-Guide-%252528how-to-use%252529%257Clang%253Den&javax.portlet.begCacheTok=com.vignette.cachetoken&javax.portlet.endCacheTok=com.vignette.cachetoken